1. Field of the Invention
The present invention relates to image processing apparatus and method for automatically selecting a substitute output device substituted for an indicated output device, and a storage medium for storing a program to execute the image processing method.
2. Related Background Art
A color printer has a different range capable of reproducing color (referred as color gamut hereinafter), in accordance with characteristics (ink characteristic, toner characteristic, recording method and the like) of the printer.
FIG. 1 shows an example of such the color gamut. In the drawing, x and y coordinates called as chromaticity coordinates are frequently used in a case where the color gamut of the color printer (or color device) is represented in a two-dimensional area. Further, the areas respectively indicated by the solid line, the dashed line and the alternate short and long dashed line represent the color reproducible areas of color printers A, B and C, respectively. As apparent from FIG. 1, the color gamut of the printer A is wider than that of the printer C, the color gamut of the printer C is wider than that of the printer B, and the color gamut of the printer B is completely included in the color gamut of the printer A. Namely, all the colors reproducible by the printer B are also reproducible by the printer A.
FIG. 2 shows an example of the structure of a printer profile according to ICC (International Color Consortium) profile specifications. The profile is composed of a header section which stores therein information used in profile management, a tag table which stores therein pointers used to access tag data, and a tag data storage section which stores therein a required tag, an optional tag and a private tag. Concretely, the header section stores therein device information representing which device (e.g., monitor) the profile corresponds to, CMM (color management module) information representing which CMM the profile is used in, and the like. The tag data storage section stores therein profile description information for discriminating the profile. As the profile discrimination information, e.g., information representing a maker name and a product name such as xe2x80x9cCANON LBP-2030xe2x80x9d is stored. Further, the required tag includes a gamut tag as the data representing the color gamut of the printer.
FIG. 3 is a view showing the data structure of the gamut tag. The gamut tag stores therein the data for checking whether or not input device-independent color (CIE XYZ color space or CIE LAB (referred as L*a*b* hereinafter) color space) can be output by the printer in question. If the gamut tag has the data for checking all combinations of input data, the data capacity of the tag becomes tremendously large. Therefore, in order to prevent this, generally, the three-dimensional input color space is divided into plural grids, the gamut tag has the data only for the grids, and interpolation based on the data of the peripheral grids is performed for the input color not corresponding to any grids to obtain the output color. In the example shown in FIG. 3, the input L*a*b* color space is divided into four grids. Then, for each grid, if the input color data can be output by the printer, ON data is stored in the tag, while if the input color data can not be output, OFF data is stored. Further, for the color data between adjacent grid points (i.e., color data not corresponding to any grids), the interpolation based on the data of the grids being the vertexes of the cube surrounding or enclosing the data in question is performed, and either of the ON and OFF data is obtained for such the data.
FIG. 4 is a view for explaining the gamut check function of the CMM. The gamut check function is to judge whether or not input R (red), G (green) and B (blue) data of which characteristics are defined by a source profile (i.e., scanner profile or monitor profile) can be output by the printer of which characteristic is defined by a printer profile. Concretely, a gamut check function in the CMM checks whether or not the input R, G and B data can be output by the printer, on the basis of the information of the source profile and the data in the gamut tag of the printer profile. If the data can be output by the printer, the gamut check function outputs the ON data, while if the data can not be output, the function outputs the OFF data.
FIG. 5 is a view for explaining in detail the process of the gamut check function shown in FIG. 4. The input R, G and B data are initially converted into L*a*b* data on the basis of the information (i.e., data necessary to convert R, G and B data into data of device-independent L*a*b* color space) in the source profile. Then, it is judged whether or not the obtained L*a*b* data can be output by the printer, by using the data of the gamut tag in the printer profile. If the data can be output by the printer, the gamut check function outputs the ON data, while if the data can not be output, the function outputs the OFF data.
As explained above, it has been known that, by using the data of the gamut tag in the printer profile, it is possible to judge whether or not the color data can be output by the intended printer.
In the conventional network system, if the color data can not be output by the selected color printer due to mass printing, some error or the like, the image data can not be output by using a substitute color printer automatically selected in view of color reproduction.
That is, in the conventional system, if the error occurs, a user himself must select another color printer and newly instruct the selected printer to perform printing.
Further, in recent years, as a network system for use in the case where the data can not be output by the selected printer, it has been thought the system for automatically selecting another printer according to whether or not an original is a color original. That is, if the original is judged as the color original, a color printer is automatically selected as the substitute printer.
However, in such the system, color reproducibility is not considered when the color printer is selected. As described above, since the gamut is different according to a kind of printer, the color reproducibility is also different according to the kind of printer. For this reason, there is a problem that the image of which tint is different from that expected by the user is output. That is, if the image having different tint is output, the user must again output the image by using another color printer.
An object of the present invention is to enable an image processing apparatus to automatically select a substitute output device which is substituted for an indicated output device and can reproduce a color image equivalent to that output by the indicated output device.
Especially, the object is to enable the apparatus to obtain a satisfactory substitute output by automatically selecting the substitute output device substituted for the indicated output device, on the basis of gamut data important in the color reproduction.
In order to achieve the above object, it is provided the image processing apparatus which automatically selects the substitute output device substituted for the indicated output device, the apparatus comprising:
a judgment function for judging whether or not output is to be performed by the indicated output device; and
a selection function for selecting, in a case where it is judged by said judgment function that the output is not to be performed by the indicated output device, the substitute output device on the basis of color reproduction information of output devices being candidates for the indicated output device.
Another object of the present invention is to enable an image processing apparatus to easily construct a system from an existing system by selecting a substitute output device with use of gamut data stored in a profile used for a color matching process.
In order to achieve the above object, it is provided the image processing method which automatically selects the substitute output device substituted for an indicated output device, the method comprising the steps of:
inputting color gamut information stored in the profile corresponding to plural output devices used in the color matching process; and
automatically selecting the substitute output device on the basis of the color gamut information of the indicated output device and the color gamut information of the other output devices.
Still another object of the present invention is to enable a user to select a substitute output device according to user""s purposes.
In order to achieve the above object, it is provided a method which automatically selects the substitute output device substituted for an indicated output device, the method comprising the steps of:
inputting color gamut information of the indicated output device and color gamut information of output devices being candidates for the indicated output device;
selecting the substitute output device on the basis of the color gamut information of the indicated output device and the output devices being the candidates for the indicated output device; and
grouping the output devices connected to a network,
wherein the other output devices in a group to which the indicated output device belongs are handled as the output devices being the candidates for the indicated output device.
Other objects and features of the present invention will become apparent from the following detailed description and the attached drawings.